The relationship between total scores and interrelationships among certain similarly named subtests of the Metropolitan and Stanford Achievement Tests are considered. The correlation of total scores for the two batteries was .89, indicating that the batteries measure essentially the same things. If one were interested in selecting a battery to simply rank order students, either battery would be appropriate. Evidence of uniqueness of similarly named subtests in the two batteries was noted by the range of .49 to .69 correlations. Uniqueness of this magnitude is important in selecting a battery for measurement of outcome of instruction when one is interested in fitting the test to the curriculum. This is statistical evidence indicating that responsible school personnel need to analyze the curriculum by subject areas, consider future goals and innovations, and administer various subtests of various batteries to appropriate instructional personnel when selecting an achievement battery for diagnosis of pupil progress by areas and making decisions about the curriculum. (Author)